Book-check



1. c. SCHMIDT.

Y DOOR CHECK.

APPLICATION min Nov. 20. i915.

Patented Ag. 15, 1916.

'UNTTED STATES PATENT orrron.

JOHN C. SCHMIDT, OF CHICAGO, ILLINOIS.

DOOR-CHECK.

Application filed November 20, 1915.

To all whom it may concern:

Be it known that I, .lor-IN C. SCHMIDT, a citizen of the United States, residing at 1538 lVolfram street, in the city of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Door-Checks, of which the following is a specification.

My invention relates to improvements in door checks and more particularly to devices of this class in which the door is slowed down or retarded near the limit of its closing movement by a liquid checking device.

The objects of the invention are to provide a device of this character of simple, strong and durable construction which will be etlicient and reliable in operation, comparatively light in weight, and easy to fit and adjust to the door, to so arrange the parts thereof that a door, to which the device is fitted will be rapidly and automatiu cally closed when released after it is opened and will be slowed down or retarded near the limit of its closing movement to pre- Vvent slamming the door. rlhese and other objects -I accomplish as hereinafter set forth in the following description and as more particularly pointed out in the appended claims, reference being had to the accom panying drawings in which an embodiment of my invention is shown.

In the drawings Figure 1,y represents a fragmentary horizontal section through a door and its frame to which my improved door check is fitted; the door being shown closed in full lines and partially open in dotted lines and the door check also being shown in its corresponding position in full and dotted lines. Fig. 2, is a side elevation of a fragment of a door and its frame with the improved check fitted thereto. Fig. 3, is a longitudinal section enlarged through the liquid check. Fig. 4, is a fragmentary View of a portion of the inner wall of the hollow cylindrical casing of the check. Fig. 5, is a detached perspective view of the removable cover' of the casing with the cam attached thereto. Fig. 6 is an enlarged longitudinal section through the tubular spring containing arm, with the spring and a portion of the connecting chain shown therein.

In referring to the embodiment of my invention shown in the accompanying drawings in detail like numerals designate like parts.

Specification of Letters Patent.

Patented Aug. 15, 1916.

serial No. 62,454.

In order that my improved device and its operation may be clearly understood, l have shown it fitted in properposition and attached to a door and its frame, the door being designated by the numeral 1, and the door frame by 2. v

The device in brief comprises a door returning or closing mechanism and a check for slowing down orretarding the returning or closing movement near the limit of its range. As shown, the door returning or closing mechanism is composed of a plurality of arms and a tubular casing 3, which is secured lengthwise upon the door surface near the top thereof by a. single screw 4 and in such manner that it may have a slight rocking movement upon said screw.

An arm or lever 5 is connected at one end to a check as will be more clearly hereinafter explained and at its opposite terminal to the outer extremity of an extensible member or arm which in turn is pivoted at its inner end to a bracket 6, attached to the door frame. The eXtensible member or arm has a turnbuckle 7, and a screw bar 8, having one end fitted in a screw threaded opening in the turnbuckle and its opposite end pivoted between the ears of the bracket.

A return spring 9 is housed within the tubular casing 3, being held therein by an annular stop or shoulder 10 in one end of the casing and a chain 11 extends through the stop casing and spring and carries a disk 12 at its inner end which bears against and compresses the spring as the door is opened. The outer end of the spring is attached to a projection 13, upon a circular track or support 14, arranged at the inner end of the arm or lever 5, the chain being bent partially around and supported by the track as it is withdrawn from the tubular arm 3, when the door is opened.

The check for slowing down or retarding the closing of the door near the limit of its movement has a cylindrical casingl, the lower end' of which is permanently closed by a bottom 15a and the top mouth of which is also closed by a removable cover 16 fastened thereon by screws 17. v

The casing 14 is provided with ears 18 through which screws 19 are fitted to fasten the casing to the door as shown in Fig. 2. rlhe interior of the casing has a lower chamber 20 and an upper larger chamber 21, and the circular walls of these chambers are concentric, the wall of the upper chamber being joined to the wall of the-lower chamber by an annular shoulder or horizontal abutment 92, see F ig. 3. The lower chamber forms a receptacle for the checking fluid which is preferably oil, and a piston 23, is tted therein so that it can both reciprocate and also partially turn with the casing. The piston is provided with an upstanding stem or rod 2i, which extends up and through the cover 1G, of the casing and the arm or lever 5, is suitably -fastened to the projecting upper terminal of the stem by a screw Q5. cheek valve 2G, is arranged in the piston to permit the return of the Huid to the lower chamber as the piston is raised. The stein or piston rod 2l, is made hollow to provide a passage 27, through which the iiuid can slowly flow as the check is operated from the lower chamber to the upper chamber, and regulating mechanism.controlling the fluid flow is arranged within the passage and comprises a screw sleeve QS and an adjusting screw bar 29, extending` through said sleeve. rIlhe size or area of the passage at one point is regulated by the adjustment oi' the sleeve and screw bar and thus the rapidity of the operation of the check can be varied. rI`he passage 27, extends from the bottom surface of the piston throughout the piston and its stem as shown in Fig. 3, and an intermediate shoulder 30, is formed therein in which an opening 3l, is provided through which the fluid iows and which is controlled by the regulating mechanism. An opening 32 is formed in the wall oit' the stem above the shoulder 30 through which the oil passes out from the interior of the stem into the upper chamber over the piston. A lateral enlargement or oi'set 33 is located upon the -stem over the piston and a stationary depending cam 3st is arranged on the under surface of the cover 1G, and engages with the otl'set to depress the piston as it is partially turned within the casing by the oper ation of the door. The piston is raised and is maintained in its elevatedposition by a spring 35, which is fitted loosely in the lower portion of the passage Q7, with its upper end bearing against the shoulder and its lower end pressing upon the top of a vertical pin 35aas shown in F ig. 3, and which extends centrally up from the bottom of the casing. I may if I desire provide the side wall of the lower chamber with a groove or channel 36, to increase the How ot fluid as the piston is depressed. In order that the ilow of the checking fluid through the groove 36 will gradually decrease in volume as the piston is forced downward and thus slow up the piston speed, the said groove 36 is so formed that it gradually deepens from its lower extremity upward, as shown in Fig. 3, and also gradually increases in width as shown in Fig. 4. Viewing the groove from the inner side as seen in Fie. a, it will be noted that it is approximately V-shape.

The operation of the device is as follows The door being opened from the position shown in Fig. l, in full lines to the position shown in dotted lines in said Fiff. l, the arms are turned as shown and the chain partially withdrawn from the tubular casing against the tension of the spring 9. The door now being released the pull of the return spring causes it to close, and the closing movement rocks the arm or lever 5, thereby partially rotating the piston and its stem and causing the offset 33 to slide upon the surface of the cam 34, and reciprocate the piston in one direction. This places great pressure upon the fluid causing it to ilow through the passage in the stem and also slowing up or retarding the swinging movement of the arm or lever 5 and consequently checking the closing of the door.

lVhile I have. illustrated and described a preferred form of construction for carrying my invention into eii'ect, this is capable of a wide range of variation, alteration, modification and change without departing from the spirit of my invention. I therefore, do not wish to be limited to the construction herein shown and described but desire to avail myseltl of all such variations, alterations, modifications and changes as fairly fall within the scope of the appended claims or may be construed to be within the scope thereof by invoking the doctrine of equivalents.

What I claim as my invention and desire to secure by Letters Patent is 1. In apparatus ot the class described, an arm, pivoted to a door frame, a hollow casing secured to the door, a 4return spring within said hollow casing, a chain connected to said return spring, a fluid check attached to the door, a lever' operatively connected at its inner end to said check and pivoted at its outer extremity to the arm pivoted tothe door frame, a projection on said lever to which the chain is attached, and an annular track on the inner end of the lever upon which said chain winds.

2. In an apparatus of the class described, an arm pivoted at one end to a door frame, a hollow casing secured to the door, a return spring within said casing, a chain eX- tending loosely through the hollow casing, a disk at the inner end of the chain bearing against the inner end of the return spring, a check attached to the door, an operating lever extending from said check and pivoted at its outer extremity to the arm pivoted to the door frame, and means arranged on said lever upon which the outer portion of the chain is supported and wound.

3. In a door check, a hollow cylindrical casing having a closed bottom, a lower chamber forming a receptacle for fluid and an upperl chamber, a piston mounted for reciprocation in the lower chamber and also adapted to partially turn therein, :t cover on the casing, a. stem integra-l with said piston and extending vertically up therefrom through the cover, said piston and stem being provided with a central vertical opening extending therethrough, and :t medial portion of said opening being contracted to -form a valve seat, a. lateral offset formed on the stem, a stationary cam depending from the cover against which the oset engages, t regulating screw bar in the upper portion of the opening in the stem coperating with the contracted valve sea-t to control the volume of Huid flow, e centering pin extending up from the bottom of the casing, and projecting into the lower portion of the centra-1 vertical opening, and :t spring in the opening located between the top of the pin und the valve sent.

In testimony whereof l have hereunto set my hand.

Chicago, Illinois, November 17th, A. D.

JOHN C. SCHMIDT.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

